The present invention relates generally to stator vanes for gas turbines and, more particularly, to a novel and improved profile for a third stage stator vane.
In the design, fabrication and use of turbine engines, there has been an increasing tendency toward operating with higher temperatures and higher operating pressures to optimize turbine performance. Also, as existing turbine airfoils and stator vanes reach the end of their life cycle, it is desirable to replace the airfoils, while simultaneously enhancing performance of the gas turbine through redesign of the airfoils to accommodate the increased operating temperatures and pressures.
Airfoil profiles for gas turbines have been proposed to provide improved performance, lower operating temperatures, increased creep margin and extended life in relation to conventional airfoils. See, for example, U.S. Pat. No. 5,980,209 describing an enhanced turbine blade airfoil profile. Advanced materials and new steam cooling systems now permit gas turbines to operate at, and accommodate, much higher operating temperatures, mechanical loading, and pressures than is capable in at least some known turbine engines. As a result, many system requirements must be met for each stage of each compressor used with the turbine engines in order to meet design goals including overall improved efficiency and airfoil loading. Particularly, the airfoils of the stator vanes positioned within the compressors must meet the thermal and mechanical operating requirements for each particular stage.
Past efforts to meet design goals and desired requirements have provided coatings on the airfoil, but such coatings may not be robust enough or permanent to provide design goals and desired requirements. Accordingly, it is desirable to provide an airfoil configuration with a profile meet to design goals and desired requirements.